The present invention relates generally to improvements in touch panel displays. More specifically, the present invention relates methods and apparatus for providing enhanced security to signals from a touch panel display, such as the transparent touch panel displays utilized in automatic teller machines.
A transparent touch panel display, or touch screen, produces electrical signals which correspond to a position on the touch screen being touched. Touch screens have found wide spread use as user input devices for electronic transaction terminal devices such as automated teller machines (ATMs) and point of sale (POS) terminals. During certain payment, cash withdrawal, or other transactions, a personal identification number (PIN) is entered on the payment terminal""s touch screen by the user as a form of identification. Since this PIN is considered highly confidential, it could be extremely damaging to the user""s account if a third party was able to eavesdrop on the electrical signals from a touch screen during PIN entry and reproduce those signals during a subsequent transaction to falsely identify themselves as the PIN assignee. As devices such as ATMs are located in less and less carefully supervised locations, efforts at fraud may be more determined and sophisticated. Thus, enhanced security features are highly advantageous.
Accordingly, it would be highly advantageous to provide enhanced security by preventing a third party from eavesdropping on the electrical signals produced by a touch screen during the entry of confidential information, such as a PIN or the like.
The present invention advantageously provides methods and apparatus to prevent third parties from eavesdropping on a touch screen and reproducing meaningful information from the electrical signals produced by the touch screen during the entry of a PIN or other confidential information. The touch screen may operate resistively, capacitively, or in another suitable manner. According to one aspect, the present invention provides a varying reference voltage for input to a touch screen panel. The varying reference voltage is utilized by the touch screen to generate an x-axis signal and a y-axis signal which correspond to a position touched on the touch screen. According to another aspect, the present invention provides a varying reference current for input to a touch screen panel.
A more complete understanding of the present invention, as well as further features and advantages of the invention, will be apparent from the following detailed description and the accompanying drawings.